Accurate quantification of astaxanthin from Haematococcus pluvialis using DMSO extraction and lipase-catalyzed hydrolysis pretreatment

Haematococcus pluvialis accumulates high contents of astaxanthin and is considered as an important source of natural astaxanthin production. Fast and accurate quantification of astaxanthin is needed to evaluate the quality of microalgal sources for astaxanthin extraction and to monitor the H. pluvialis cultivation process. In the present study, a less-invasive method for astaxanthin accurate quantification was developed. Dimethyl sulfoxide (DMSO) was used as an extraction solvent to improve the membrane permeability of H. pluvialis. Cholesterol esterase was used to hydrolyze astaxanthin esters via incubation at 36 °C for 30 min. The detection of astaxanthin after hydrolysis was achieved by high performance liquid chromatography (HPLC) within 10 min using a C18 column. The astaxanthin content measurements after enzymatic pretreatment were 1.5-1.7 times higher than that measured after saponified pretreatment. DMSO solvent extraction combined with lipase-catalyzed hydrolysis followed by HPLC detection is proposed for the accurate quantification of astaxanthin in H. pluvialis.